Renewable Energy 52 (2013) 222e229. Contents lists available at SciVerse ScienceDirect. Renewable Energy

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1 Renewable Energy 52 (2013) 222e229 Contents lists available at SciVerse ScienceDirect Renewable Energy journal homepage: Evaluation of wind energy potential as a power generation source for electricity production in Binalood, Iran Ali Mostafaeipour a, *, Ahmad Sedaghat b, Morteza Ghalishooyan c, Yagob Dinpashoh d, Mojtaba Mirhosseini e, Mohammad Sefid f, Maryam Pour-Rezaei g a Industrial Engineering Department, Yazd University, Yazd, Iran b Mechanical Engineering Department, Isfahan University of Technology, Isfahan, Iran c Civil Engineering Department, Ferdowsi University, Mashhad, Iran d Department of Water Engineering, University of Tabriz, Tabriz, Iran e Islamic Azad University of Semnan, Mechanical Engineering Department, Semnan, Iran f Mechanical Engineering Department, Yazd University, Yazd, Iran g Management Department, Yazd University, Yazd, Iran article info abstract Article history: Received 3 April 2012 Accepted 18 October 2012 Available online 25 November 2012 Keywords: Wind Potential Economic evaluation Feasibility Binalood Iran In this paper, the hourly measured wind speed data for years 2007e2010 at 10 m, 30 m and 40 m height for Binalood region in Iran have been statically analyzed to determine the potential of wind power generation. The study showed that the long-term wind speeds were found to be relatively high. The numerical values of the dimensionless Weibull shape parameter (k) and Weibull scale parameters (c) were also determined. Based on these data, it was found that the numerical values of the shape and scale parameters for Binalood varied over a wide range. The yearly values of k at 40 m elevation range from to with a mean value of 2.186, while those of c are in the range of 7.683e8.016 with a mean value of However, the yearly mean wind speed, mean power density and power density of Binalood at 40 m height are found as m/s, W/m 2 and (kwh/m 2 /year) respectively. The results show that Binalood has available great wind energy potential for grid connection system. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Global climate change and increasing worldwide demand for electricity requires need for harnessing different kinds of renewable energies like wind energy in many countries in the world including Iran. The climate change challenge could become a force for good in humanity. This challenge is about programming, cooperation, planning ahead and thinking of the complex interconnectedness of social, economic, political, cultural and environmental systems [1]. Global warming and climate change are the most critical issues facing the world today [2]. Interest has recently risen toward renewable energy (RE) sources especially wind energy for electricity generation in many countries. Countries have tried to accelerate solutions for wind energy generation design parameters [3]. Electrical power generation by wind turbines grew during the second half of the 20th century and oil price rises in the 1970s * Corresponding author. Tel.: þ , þ address: mostafaei@yazduni.ac.ir (A. Mostafaeipour). promoted intense interest in its value as a fuel-free, renewable energy source in many European and north American countries [4]. The main purpose of this article is to estimate the wind energy potential of the Binalood region in Iran. For this purpose, the collected wind data from the location should be properly analyzed and interpreted. Usually, long-term hourly or three hourly wind data from the meteorological site can be used for the analysis. Collected wind speed data should be carefully extrapolated to represent the wind profile of the site. Feasibility study is the first step for knowing whether a location is suitable or not. Second step is to do a field wind speed measurement for short period of time which is usually one year. Clearly, one year wind speed data is sufficient to represent the long-term variations in the wind profile within an accuracy level of 10 percent [5e7]. For this study, only the primary step was done to estimate the wind potential of Binalood. Iran joined the group of countries which were using wind energy for electricity production in As reported by Fadai [8], the construction of first wind power station (the 25 MW and 60 MW power stations at Manjil) began in Iran in At the present time, Manjil and Binalood wind farms are two major wind sites in Iran. Recently, about 0.17 percent of Iran s required /$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.

2 A. Mostafaeipour et al. / Renewable Energy 52 (2013) 222e electricity has been provided by wind energy. The Binalood site (Fig. 1), which is locally called Dizbad, is located between major cities of Mashhad and Neyshabour. Iran generated 47 MW of electricity from wind power (ranked 30th in the world) in 2006, an increase of about 47% over 32 MW in Total wind generation in 2004 was 25 MW out of 33,000 MW total electrical generation capacity for the country. In 2008, Iran s wind power plants in Manjil area (in north of Iran) and Binalood produced 82 MW of electricity. By 2009, Iran had wind power installed capacity of 91 MW [9]. Table 1 illustrated top twenty wind speed stations located in different parts of Iran. Clearly, there are some other locations in Iran with higher wind speeds and potentials, but Iranian Renewable Organization (SUNA) chose some other locations for installation of the 40 m towers to measure wind speeds for preparing of the Iranian wind atlas. Fig. 1. Edited Iran map with terrains, Binalood is the site studied in the current study [Source:

3 224 A. Mostafaeipour et al. / Renewable Energy 52 (2013) 222e229 Table 1 Wind speed stations located in different parts of Iran. Rank Location Wind speed (m/s) 1 Khaf Lootak Fedesk Moaleman Bardkhoon Bojnoord Hadadeh Rafsanjan Afriz Mayan Abadeh Ghadamgah Kish Nosratabad Namin Varzaneh Jangal Eghlid Sarakhs Maraweh Tapeh 4.8 Manjil and Roodbar regions were first locations in Iran which wind turbines were installed. First, two sets of 500 kw turbines with total of more than1.8 million kwh per year production were installed to generate electricity [9,10]. Wind energy potential in Iran has been studied and analyzed for some areas such as Shahrbabak in Kerman province [11], Isfahan [12], Manjil in Gilan province [13], Yazd [14], Tehran [15], and Semnan [16] provinces; there are also studies about feasibility of offshore wind turbine installation in Iran and comparison with the world [17], future of renewable energies in Iran [18] and renewable energy issues in Middle East compared with Iran [19]. Purpose of this study is to determine feasibility of wind energy potential in Binalood which is located in northeast province of Khorasan. This paper presents research work involved in determining the feasibility of deploying wind driven devices for Binalood region in northeast of Iran. The next section offers a discussion of yearly Weibull parameters and characteristic speeds is described thoroughly. The wind pattern is presented in Section 3. The monthly Weibull parameters and characteristic speeds are brought forward in Section 4. Also reason for choosing the site is illustrated in Section 5. Finally concluding remarks are presented in Section Yearly Weibull parameters and characteristic speeds There should be long-term meteorological observations for the Binalood area in order to accurately predict and also to calculate the wind potential and energy. Clearly, wind speed is a random variable, and probability density functions are calculated from variation of wind speed over a period of time. There are several probability density functions like Rayleigh function, gamma function, beta function, lognormal function, Weibull distribution function, and logistical function, which can be used for frequency of wind speed curve [20,21]. Weibull distribution function is the most popular and best probability distribution for wind speed in studies [11,16,20,22,23]. Weibull function has shown an acceptable distribution function that accurately fit the wind speed frequency in the given duration course. Weibull function is determined by its two parameters i.e. k (dimensionless) and c (m/s) [22]. The shape parameter k shows skewness rate of Weibull curve. The higher values for k (between 2 and 3) means the curve is more skewed toward higher wind velocities, and lower values for k (between 1 and 2) means the curve is more skewed toward lower wind velocities, thus indicating that lower wind velocities are more probable to happen. The scale parameter c shows the peak value of the Weibull curve. In fact, higher values for c mean the distribution is spread over a wider range [11]. 3. Wind pattern 3.1. Monthly mean wind speeds Monthly mean wind speed values and also standard deviation of Binalood are presented in Table 2. Hourly wind data collected over a period of between 2007 and 2010 at three different heights of 10, 30, and 40 m respectively. Most of the monthly mean speed wind values are between 5.00 and 8.00 m/s. The highest whole year average wind speed at elevations of 10, 30, and 40 m occur on July (7.825 m/s), July (8.125), and July (8.615) respectively. For different years, the trends of monthly mean wind speeds and standard deviations are almost similar. December at different elevations from 2007 to 2010 showed the minimum mean wind speed value of m/s, 5.598, and at 10, 30, and 40 m elevations respectively. Binalood, therefore, has good potential for developing wind energy sources for electricity production. By analyzing the 48 months of wind speed data at three different elevations, it can be concluded that the wind speed distribution differs remarkably from one month to the next. The monthly and yearly standard deviation values are mostly between 1.3 and 2.3 m/s Yearly Weibull parameters and characteristic speeds At 10 m elevation, Table 3 shows the average of Weibull scale parameter (c) is m/s, Weibull shape parameter value (k)2.118 and mean wind power density (P/A) W/m 2 for period of 2007e2010. Mean wind energy (E/A) is also kwh/m 2 /year for same period. Clearly, values for each year are also illustrated in this table. The mean values of Weibull scale parameter (c) m/s, Weibull shape parameter value (k) and mean wind power density (P/A) W/m 2 at 30 m height are illustrated. Mean wind energy (E/A) is also kwh/m 2 /year for period of 2007e It also shows that higher values of k and c yield to higher values of power density and energy which occurred in Also, Table 3 illustrates mean Weibull scale parameter (c) m/s, Weibull shape parameter value (k) and mean wind power density (P/A) W/m 2 of the site at 40 m height. Mean wind energy is kwh/m 2 /year for the same period too. Data shows that 2008 is the most favorable year for wind energy harnessing which is similar to the values at 30 m elevation. This means that, under the current wind turbine technique, this area is suitable for year round large-scale electricity generation due to the cost factor. However, utilization of small-scale applications for house appliances and heating is also possible. A classification [16,24] indicated the wind characteristics and evaluations as following: P A < 100 W is poor m2 P A z400 W is good m2 P A > 700 W is great (1) m2 Based upon the above classification, the Binalood region is almost a good location.

4 A. Mostafaeipour et al. / Renewable Energy 52 (2013) 222e Table 2 Yearly mean wind speeds and standard deviations for Binalood region. Month Parameter 10(m) 30(m) 40(m) Whole year Whole year Whole year Jan v s Feb v s Mar v s Apr v s May v s Jun v s Jul v s Aug v s Sep v s Oct v s Nov v s Dec v s Yearly v s Another classification done by European Wind Energy Association (EWEA), the wind characteristics and categories are indicated as below [24]: Fairly good (6.5 m/s, z300e400 W/m 2 ); Good (7.5 m/s, z500e600 W/m 2 ); Very good (8.5 m/s, z700e800 W/m 2 ). According to the above classification, Binalood is a fairly good location for wind turbine installation. Also, the following classification shows that the city is categorized as fairly good. The Binalood wind site has a noticeable potential for development and providing more electricity from wind energy, and also exporting electricity to the neighboring countries. Having suitable basic factors of a wind site, such as: acceptable speed and density and low turbulence intensity of the wind, near access roads to the site and close location of transfer lines and electric network of the region, caused the site to be taken under serious consideration for producing electricity in future Monthly mean wind speed It is observed from Fig. 2 and Table 2 that Binalood has high mean wind speed. The monthly mean wind speed at 10 m height is 6.555, 6.238, 6.727, and m/s respectively from 2007 to The maximum mean 4 years wind speeds occur in June and July, whilst minimum mean 4 years wind speeds start from November to January. Fig. 3 illustrates the actual monthly mean wind speed of the region at 30 m height. The values from 2007 to 2010 are 6.636, 6.719, 6.491, and m/s respectively. The maximum and minimum actual mean wind speeds of 4 years period occur in July and February, respectively at 30 m elevation. Clearly, when the height increases, the speed also increases. The wind speed is given as at 10 m above the ground level, but, the wind speed is given as m/s at 30 m above the ground level. The higher value of wind speed is supposed to occur at a higher level above the Table 3 Yearly Weibull parameters and characteristic speeds (at 10 m height, in m/s), wind power and energy density. Year Height (m) k c (m/s) V mp v op v (measured) P/A (W/m 2 ) E/A (kwh/m 2 /year) Whole year Whole year Whole year

5 226 A. Mostafaeipour et al. / Renewable Energy 52 (2013) 222e229 Fig. 2. Monthly mean wind speed at 10 m elevation (2007e2010). Fig. 4. Monthly mean wind speed at 40 m elevation (2007e2010). ground. It is an exception, because of some natural parameters like ground specification or turbulence. At 40 m height, the actual monthly mean wind speed 40 m height is 6.014, 6.099, 7.834, and m/s respectively from 2007 to 2010 which is illustrated in Fig. 4. The maximum and minimum mean 4 years wind speeds occur in July and February, respectively at 40 m elevation. The monthly mean wind speeds at different elevations (Figs. 2e4) indicates that the whole year wind speed has the lowest value in the month of December and the highest in the month of June, In Binalood, the higher heating demand also occurs from October to April, which can be grouped as the cold season. The wind energy may be applied as a supplement to the current gas or electricity heating. But it is applicable all the year for supplying required energy for different sectors Mean wind speed at different hours The annual hourly mean wind speed is demonstrated in Fig. 5. This figure shows hours of day that have a suitable wind speed in all over the year at three different heights from 2007 to Best wind speeds occur at 15 PM in the year. The cumulative distribution function is helpful for estimation of the time for which wind is within a certain velocity interval. Fig. 6 presents the cumulative distribution curves of the studied wind speeds for Binalood at three different heights. It can be noted that, for example, the wind speed at 10 m, 30 m and 40 m heights is greater than 4 m/s for most of the time in the year. The 4 m/s wind speed limit is important, because it is the cut-in speed of many commercial turbines. The cut-out speed is usually between 20 and 25 m/s However, the cut-out wind speed does not exceed 25 m/s at this site. 4. Monthly Weibull parameters and characteristic speeds The monthly Weibull parameters of k and c were calculated (Tables 4e6). Clearly, the monthly wind speed distribution (2007e 2010) differs over a whole year. At 10 m height (Table 4), values of c are between and The minimum value of c is found in July, but the maximum belongs to December. K value ranges from to Maximum wind power density of W/m 2 occurs on December whilst lowest is for month of July with value of W/m 2. Whole year average wind energy density of region is also kwh/m 2 /month. Clearly, December gains maximum wind energy density with value of kwh/m 2 /month. The monthly Weibull parameter characteristic speeds (at 30 m height), wind power and energy density are given in Table 5. The biggest value of the monthly mean power density occurs as W/m in January and the lowest value of it occurs as W/m in July. By examining the data, it is seen that the Fig. 3. Monthly mean wind speed at 30 m elevation (2007e2010). Fig. 5. Mean wind speed at different hours of the year-binalood.

6 A. Mostafaeipour et al. / Renewable Energy 52 (2013) 222e wind speed limit is important, because it is the cut-in speed of many commercial turbines. The cut-out speed is usually between 20 and 25 m/s However, the cut-out wind speed does not exceed 25 m/s at this site. 5. Advantages of Binalood for installation of turbines 5.1. Economic advantage An important and major factor for construction of a wind farm in any location is profitability of the project. Economic evaluation for installing wind turbines in Binalood region illustrated that the site is suitable for this purpose Environmental issues Fig. 6. Cumulative density at three heights for Binalood. changes of monthly mean wind speed and power density are proportional and the values are especially bigger in October, November and December months. Whole year average wind energy density of region is also kwh/m 2 /month. Clearly, December gains maximum wind energy density with value of kwh/ m 2 /month. The monthly mean power density, energy density, k and c values at 40 m elevation are given in Table 6. The biggest actual value of the monthly mean power density occurs as W/m 2 in December and the lowest value of it occurs as W/m 2 in July. Whole year average wind energy density of region is also kwh/m 2 /month. Clearly, December gains maximum wind energy density with value of kwh/m 2 /month. Values of c are between and The minimum value of c is found in February, but the maximum belongs to December. K value ranges from to at this elevation. By examining data of Table 6,it is seen that the changes of monthly mean wind speed, power density, and energy density are proportional and the values are especially bigger in December, November and May. Clearly, when the height increases, the speed and power density also increase. The maximum occurrence probability of the site at 10 m height is obtained as 15.5% at the wind speed of around 6.6 m/s. Maximum occurrence probability of the site at 30 m and 40 m heights are obtained respectively as 11.9% and 11% at the wind speeds of around 6.9 m/s and 7.1 m/s. The wind speed at 10 m, 30 m and 40 m heights is greater than 4 m/s for most of the time in the year. The 4 m/s An important environmental advantage of wind energy is that it does not pollute the atmosphere with toxic chemicals. The impact of wind turbines on avian population is an important issue. Studies conducted at the Binalood area indicated low levels of bird mortality due to collision with wind turbines. Wind turbines create some noise during the operation. Clearly, noise is an unwanted sound. In the 80 s, most of the turbines were noisy which annoyed many residents even at the far distance to the wind farms. Now, modern turbines with new design modifications are much quieter [5]. The noise emitted from the turbines is not a matter of great concern, because the residential areas are not very close to the Binalood wind farm. The impact of the wind turbines on scenic beauty of the landscapes is a barrier for wind farm establishment in any area. Aesthetically, there are different opinions among people [5]. Fortunately, this issue has not been important in Iran, because people are in favor of any renewable energy projects. As a matter of fact, Manjil wind farm in north of Iran is located in heart of the city. Binalood wind farm is not surrounded by private farms or residential areas. Local people are quite calm which have accepted new renewable technology Durable flow of wind The average wind speed of Binalood is great, because it is located in the natural wind tunnel with almost permanent wind flow. The average wind speed of Hossein Abad meteorology station with 10 km distance from Binalood is 7.7 m/s (data were collected from 1996 to 1997 at height of 20 m and from 1998 to 2000 at height of 10 m). Table 4 Monthly Weibull parameter characteristic speeds (at 10 m height, in m/s), wind power and energy density. Month k c (m/s) V mp v op v (measured) Wind power density (W/m 2 ) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Whole year Wind energy density (kwh/m 2 /month)

7 228 A. Mostafaeipour et al. / Renewable Energy 52 (2013) 222e229 Table 5 Monthly Weibull parameter characteristic speeds (at 30 m height, in m/s), wind power and energy density. Month k c (m/s) V mp v op v (measured) Wind power density (W/m 2 ) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Whole year Wind energy density (kwh/m 2 /month) Table 6 Monthly Weibull parameter characteristic speeds (at 40 m height, in m/s), wind power and energy density. Month k c (m/s) V mp v op v (measured) Wind power density (W/m 2 ) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Whole year Wind energy density (kwh/m 2 /month) 5.4. Soil conditions and transportation facilities It is very important to consider soil condition for turbine foundation and also road construction [25]. The area is semi-arid which the land is not suitable for agriculture. Therefore, it is an advantage for wind farm development. The Binalood region is located in an area which has easy access to other major cities by railway and main road. Hence, transportation cost and time would be very low. Also, there is not any major limitation for existing bridges and tunnels in order to transport the turbine and other equipments to the location [13] Distance to the residential areas As a matter of fact, new wind farms do not create noise because of advanced technological developments [25]. There is an acceptable distance between the Binalood region and the surrounding residential areas. It would yield to lower cost of power line, also easier operation and maintenance too. Noise is also another barrier for wind farm locations, but Binalood is far from residential zones. 6. Conclusions Since the geography of Binalood provides suitable conditions for harnessing the wind energy, it is inevitable to construct more wind farms in the region. The region has strong wind potential at 40 m height and ideally suited for large wind turbines installation. This region is highly suitable for the wind energy generation, since the wind speeds exceed 6 m/s most of the time. In this study, the mean wind speed and energy density measured at Binalood for 4 years reveals that the current technology provides the economical electricity production from the wind energy. Region has an important and significant wind resources with wind speed mean of 6.511, 6.568, and m/s for 10, 30, and 40 m respectively from 2007 to Average four year (2007e2010) wind power density at 40 m height was estimated W/m 2 with wind energy density of kwh/m 2 /year. For this area with Weibull parameters k and c, see Table 5, we can derive that the wind is sufficient during the whole year for generating the electricity. The yearly values of k (dimensionless Weibull shape parameter) at 40 m elevation, ranged from to with a mean value of 2.186, while those of c (Weibull scale parameter), were in the range of 7.683e8.016 with a mean value of Net Present Worth of project for 20 years period was estimated as positive $ 615,952. This high indicates that the region is economically feasible for wind turbine installation. Clearly, equivalent worth of cost is much less than the calculated benefit. The region must be considered as a potential area for future prospection. It is recommended that at Binalood station, there should be more wind turbines with rated power greater or equal to 600 kw like S kw which is popular in Iran. Acknowledgments The authors thank the respected reviewers with their valuable comments. References [1] Munslow B, Dempsey T. Globalization and climate change in Asia: the urban health impact. Third World Quarterly 2010;31(8):1339e56. [2] Hessami MA, Campbell H, Sanguinetti C. A feasibility study of hybrid wind power systems for remote communities. Energy Policy 2011;39(2):877e86.

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